Many blood-based assays require the separation of plasma or serum from whole blood, but this separation is often difficult and requires trained operator to perform. HIV is one example of an assay in which separation of blood or serum from whole blood is needed.
With specific regard to HIV, over two-thirds of the estimated 34 million people living with HIV/AIDS worldwide reside in developing countries, and nearly three-fourths of the 2.5 million new HIV infections in 2011 occurred in these countries. HIV viral load testing is critical for monitoring antiretroviral treatment (ART), allowing for an early detection of ART failure.
Plasma specimens are considered the most reliable medium for HIV viral load monitoring. Although centrifuges are ubiquitous in clinical laboratories to extract plasma from whole blood, centrifugation is not appropriate for point of care (POC) testing and is often unavailable in resource-constrained settings due to lack of laboratory infrastructure. Suitable alternatives are not readily available to separate a large volume of plasma from undiluted blood. Accordingly, there is a need in the art for improved POC devices for plasma and/or serum separation, especially from finger-prick or heel-prick whole blood (having a volume of, e.g., 250-500 μL).